(317c) Biomass Conversion to Hydrogen-Rich Product Gas Via Alkaline Hydrothermal Treatment

Ferguson, T., Columbia University
Park, A. H. A., Columbia University

Due to issues of environmental sustainability associated with anthropogenic carbon emission and energy security, there is strong interest to develop a new generation of energy conversion technologies that utilize domestic energy sources. As a feedstock, biomass represents a major potential for the sustainable generation of energy worldwide because it is a widespread and carbon neutral resource. Gasification and pyrolysis are the two major technologies that have been widely investigated for energy production from biomass. However, biomass has a much lower energy density as compared to fossil fuels. For this reason, in order for energy generation schemes involving biomass to be viable, they must be implemented within close proximity to the feedstock. Therefore, a distributed energy generation system would be an ideal addition to the biomass-to-energy technologies. In light of this, the present study explores a method to produce high-purity hydrogen from biomass for a fuel cell stack (e.g. PEM fuel cell). As biomass is reacted with a hydroxide (e.g., NaOH), the majority of carbon is separated as solid carbonate while the product gas is hydrogen rich. One of the main benefits of this technology is that chemical conversion can be achieved at temperatures (250 ? 300 °C) and pressures (ambient pressure) significantly lower than gasification or pyrolysis. These moderate reaction conditions would make the design of a compact reactor for a distributed energy generation system feasible. Glucose and cellulose are chosen as model biomass compounds. Each is mixed with solid NaOH prior to each experimental study. The gaseous and solid products are analyzed using analytical tools such as GC-MS and NMR, respectively. TGA/DTA data are also obtained and compared to thermodynamic calculations done on these systems. Parameters including reactant ratios of biomass to sodium hydroxide, reactor temperature, heating rate in the reactor, and vapor conditions for the cellulose system are evaluated for their effects on the conversion and selectivity for hydrogen production.